Re: File Permissions

Jens.Toerring_at_physik.fu-berlin.de
Date: 10/03/03 

Date: 3 Oct 2003 13:41:35 GMT

Stu <beefstu350@hotmail.com> wrote:
> I am running in the ksh and have a umask 000 and my file gets created
> with the permissions of 666.

> -rw-rw-rw- 1 stu developer 0 Oct 3 09:17 x

> Why does it get created as 666. Is this the default behavior of the
> UNIX?, KSH?.

Yes, 666 is some kind of default - you wouldn't like all files to
be created with the execution bit set and you can change the
behavior for the other bits via umask. But perhaps you're misunder-
standing what umask is. Contrary to a quite common believe umask
does not *set* the permissions for a newly created file, it says
which permission bits are *not* to be set. That's wky it's called
'umask' and not just 'mask'. So, by having umask set to 000 you
actually allow all bits to be set for a new file. If you want to
keep the rw bits from getting set for the new file you have to set
umask to 666:

jens@crowley:~ > umask 000
jens@crowley:~ > touch testfile
jens@crowley:~ > ls -l testfile
-rw-rw-rw- 1 jens users 0 Oct 3 15:32 testfile
jens@crowley:~ > rm testfile
jens@crowley:~ > umask 666
jens@crowley:~ > touch testfile
jens@crowley:~ > ls -l testfile
---------- 1 jens users 0 Oct 3 15:33 testfile
jens@crowley:~ >
                                  Regards, Jens 

-- 
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  \___/ens|_|homs|_|oerring

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